scholarly journals Recovering Metals from Aqueous Solutions by Biosorption onto Hydrolyzed Olive Cake

Water ◽  
2019 ◽  
Vol 11 (12) ◽  
pp. 2519 ◽  
Author(s):  
Rafael Fernández-González ◽  
María Ángeles Martín-Lara ◽  
Gabriel Blázquez ◽  
Antonio Pérez ◽  
Mónica Calero
Keyword(s):  
Heavy Metals ◽  
Nitric Acid ◽  
Aqueous Solutions ◽  
Fixed Bed ◽  
Solid Material ◽  
Hot Water ◽  
Isotherm Models ◽  
Olive Cake ◽  
Biosorption Capacity ◽  
The Impact

Olive cake obtained as a by-product from the olive oil industry has been evaluated as biosorbent of heavy metals from aqueous solutions in batch and continuous systems (fixed-bed columns). First, a complete study of effect of hydrothermal treatment with water on biosorption capacity of resulting solid was performed. Results showed that the values of biosorption capacity increased when the particle size of material decreased and the temperature of treatment increased. Then, hydrolyzed olive cake was treated by common chemicals (hot water, nitric acid, and sodium hydroxide) and the impact of chemical treatment was analyzed. The results were well reproduced by Langmuir and Freundlich isotherm models, getting maximum experimental biosorption capacities that changed between 42.34 mg/g obtained for the solid material modified by NaOH and 14.27 mg/g obtained for the solid material modified by nitric acid. Finally, laboratory tests in fixed-bed columns were performed with four different heavy metals and at three different inlet concentrations. The biosorption capacity increased from 2.83 mg/g (Cr), 4.51 mg/g (Cu), 12.30 mg/g (Pb), and 4.10 mg/g (Zn) to 3.08 mg/g (Cr), 5.17 mg/g (Cu), 13.21 mg/g (Pb), and 5.51 mg/g (Zn) when the concentration of metal ions increased, from 50 mg/L to 200 mg/L, respectively. Also, the experimental data obtained was successfully correlated with the Thomas, Yoon–Nelson, and dose–response models.

Elimination of selected heavy metals from aqueous solutions using biochar and bentonite composite monolith in a fixed-bed operation

2021 ◽  
pp. 106993
Author(s):  
Asadullah ◽  
Lupong Kaewsichan ◽  
Kuaanan Techato ◽  
Zahid Naeem Qaisrani ◽  
M.S. Chowdhury ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Aqueous Solutions ◽  
Fixed Bed

Unrevealing the biosorption capacity of freshwater algae biomasses for toxic heavy metals in aqueous solutions

2020 ◽  
Vol 184 ◽  
pp. 189-198
Author(s):  
Isha Shamshad ◽  
Sardar Khan ◽  
Said Muhammad ◽  
Muhammad Waqas
Keyword(s):  
Heavy Metals ◽  
Aqueous Solutions ◽  
Freshwater Algae ◽  
Toxic Heavy Metals ◽  
Biosorption Capacity

scholarly journals Removal of mercury (II) from aqueous solutions by multiwalled carbon nanotubes coated with manganese oxide

2019 ◽  
Vol 21 (6) ◽  
pp. 258-264
Author(s):  
Abbas Khodabakhshi ◽  
Hassan Asgarian
Keyword(s):  
Heavy Metals ◽  
Carbon Nanotubes ◽  
Aqueous Solutions ◽  
Contact Time ◽  
Structural Characteristics ◽  
Initial Density ◽  
High Concentration ◽  
Nano Composite ◽  
Mn Oxide ◽  
The Impact

Background and aims: Water pollution by heavy metals is one of the most important environmental problems. Among the heavy metals, mercury (Hg) is a very toxic metal and its high concentration can lead to impaired pulmonary and renal dysfunction. The aim of this study was to determine the amount of Hg removal by carbon nanotubes coated with manganese (Mn) oxide from aqueous solutions. Methods: In this study, multi-walled carbon nanotubes coated with Mn oxide were prepared and used to remove Hg from aqueous environments. In addition, the physical and structural characteristics of the nanotubes were determined by the X-ray diffraction (XRD). The impact of diverse variables was further investigated, including the initial concentration of Hg, the initial pH of the solution, contact time, mixing rate, as well as the amount of nano-composite and the impacts of confounders (nitrate and chloride). Finally, optimum conditions for each of these parameters were obtained by the Taguchi statistical method. Results: The XRD analysis showed that the nanotubes were properly coated with Mn oxide. Furthermore, the results demonstrated that under pH 7, the rate of mixing of 150 rpm, the contact time of 60 minutes, the amount of nano-composite of 60 mg, and the initial density of Hg 80 mg/L can be achieved by removing 95% Hg. Moreover, the confounder factors of nitrate and chloride reduced the amount of Hg removal by 4 and 5%, respectively. Conclusion: Based on the results, the nanotubes coated with Mn oxide can be used as easy and strong absorbents for the rapid absorption of Hg from drinking water and industrial wastewater.

scholarly journals Continuous Fixed-Bed Column Study Using Carbon Nano-Adsorbent Made Through Pyrolysis of Garbage Leachate on the Sand Particles for Removal of 4-Nonylphenol from Surface Water

2021 ◽  
Author(s):  
Mastaneh Safari ◽  
Iman Mosaddegh
Keyword(s):  
Surface Water ◽  
Flow Rate ◽  
Fixed Bed ◽  
Morphological Characterization ◽  
Isotherm Models ◽  
Sorption System ◽  
Equilibrium Data ◽  
Best Fitting ◽  
The Impact ◽  
Nano Adsorbent

The potential of carbon nanorods (NRs) derived from garbage leachate was assessed in a fixed-bed and batch system replacing the present costly approaches to treat surface water polluted by 4-Nonylphenol. First, the waste leachate was coated on silica particles and then pyrolysis was performed at 300 to 800℃. The optimum temperature for the production of nano-adsorbent was determined by analyses such as scanning electron microscopy (SEM) for adsorbent morphological characterization, X-ray energy dispersive spectrometry (EDS), and Raman test. Next, Freundlich, Langmuir, and UT isotherm models were used to analyze the batch equilibrium data. The impact of inlet 4-NP concentration (0.5, 1, and 2 mgL-1), feed flow rate (5, 10, and 20 mLmin-1), bed height (5, 10, and 15 cm), and bottom-up flow on the breakthrough features of the sorption system with a fixed bed was examined. The adsorption data were fitted using the well-known column models (i.e., Thomas, Yoon-Nelson, and Adams-Bohart). For all circumstances, the best fitting was obtained for the attained results using Yoon-Nelson and Thomas models, but not the Adams-Bohart model. The experimental data confirmed that increasing the inlet concentration and bed depth resulted in an increase in the adsorption capacity and a decrease in flow rate. After applying a different regeneration process, the results showed the effectiveness of the novel engineered substance as a reusable adsorbent for water treatment.

Агрономическая эффективность промышленной (голландской) технологии возделывания картофеля

2018 ◽  
Author(s):  
C. Coy ◽  
A.V. Shuravilin ◽  
O.A. Zakharova
Keyword(s):  
Heavy Metals ◽  
Regression Analysis ◽  
Positive Response ◽  
Growth Yield ◽  
Correlation And Regression Analysis ◽  
Yield And Quality ◽  
Quality Of Products ◽  
High Degree ◽  
The Impact

Приведены результаты исследований по изучению влияния промышленной технологии возделывания картофеля на развитие, урожайность и качество продукции. Выявлена положительная реакция растений на подкормку K2SO4 в период посадки. Корреляционно-регрессионный анализ урожайности и качества клубней выявил высокую степень достоверности результатов опыта. Содержание нитратов и тяжелых металлов в клубнях было ниже допустимых величин.The results of studies on the impact of industrial technology of potato cultivation on growth, yield and quality of products. There was a positive response of plants to fertilizer K2SO4 in the period of planting. Correlation and regression analysis of yield and quality of tubers revealed a high degree of reliability of the results of experience. The contents of nitrates and heavy metals in tubers was below the permissible values.

The impact of urban effluents on the coastal marine environment of Mediterranean islands

1995 ◽  
Vol 32 (9-10) ◽  
pp. 85-94 ◽  
Author(s):  
Michael O. Angelidis
Keyword(s):  
Heavy Metals ◽  
Organic Matter ◽  
Marine Environment ◽  
Suspended Particle ◽  
Pollution Source ◽  
Mediterranean Islands ◽  
Coastal Marine Environment ◽  
Coastal Marine ◽  
The Impact ◽  
The City

The impact of the urban effluents of Mytilene (Lesvos island, Greece) on the receiving coastal marine environment, was evaluated by studying the quality of the city effluents (BOD5, COD, SS, heavy metals) and the marine sediments (grain size, organic matter, heavy metals). It was found that the urban effluents of Mytilene contain high organic matter and suspended particle load because of septage discharge into the sewerage network. Furthermore, although the city does not host important industrial activity, its effluents contain appreciable metal load, which is mainly associated with the particulate phase. The city effluents are discharged into the coastal marine environment and their colloidal and particulate matter after flocculation settles to the bottom, where is incorporated into the sediments. Over the years, the accumulation of organic matter and metals into the harbour mud has created a non-point pollution source in the relatively non-polluted coastal marine environment of the island. Copper and Zn were the metals which presented the higher enrichment in the sediments of the inner harbour of Mytilene.

Metal Contamination of Stream Waters under the Impact of Tanneries

2006 ◽  
Vol 33 (2) ◽  
pp. 55 ◽  
Author(s):  
MARIA LUCIA KOLOWSKI RODRIGUES ◽  
MILTON LUIZ LAQUINTINIE FORMOSO
Keyword(s):  
Water Quality ◽  
Water Discharge ◽  
Solid Material ◽  
Total Variance ◽  
Oxygen Conductivity ◽  
Contamination Degree ◽  
Iron Aluminum ◽  
Relevant Variables ◽  
Stream Waters ◽  
The Impact

This study evaluated the contamination of water samples from Cadeia and Feitoria rivers (Rio Grande do Sul State, Brazil), affected by tannery activities. From July 1999 to April 2000, four sampling campaigns were performed at ten sites in order to evaluate selected metals and ancillary physicochemical variables. Sample preservation and analyses followed recommendations of the Standard Methods. Factor analysis was used to obtain statistical indexes representing the contamination degree of waters evaluated. The information was summarized in two principal components. The first, which accounted for 50% of the total variance, was associated to a tannery contribution and generated a contamination index. Total, Suspended and Dissolved Solids, Dissolved Oxygen, Conductivity, Chromium, Manganese, Copper, Nickel, Sodium, Calcium, Potassium, and Magnesium were the well-correlated variables with this first component. The water quality decreased from headwaters up to mouth along both streams, but the most contaminated sites were located at the lower reach of Feitoria river (Ivoti and Lindolfo Collor cities), where tanneries are concentrated. After the entrainment of Feitoria waters (São Sebastião do Caí municipality), Cadeia river also presented an increased contamination degree. The application of statistical randomization tests highlighted these same sites as significantly distinct from the others. Water contamination also showed association to flow variations, and a poorer water quality was observed during the dry period (January). The second component, in which Iron, Aluminum, and Suspended Solids were the relevant variables, was loaded with 15% of the total variance. It was linked to natural events, since higher factor scores in this component were obtained during a period of increased water discharge (October), which caused resuspension and entrainment of solid material to the rivers bed. As a final result of the study, sampling stations were classified according to the contamination degree, and graphically represented on a basin map, which synthesized the environmental diagnosis.

Hazards for Construction Workers

2017 ◽  
Author(s):  
Gavin H. West ◽  
Laura S. Welch
Keyword(s):  
Heavy Metals ◽  
Prevention And Control ◽  
Respiratory Diseases ◽  
Noise Exposure ◽  
Engineered Nanomaterials ◽  
Construction Workers ◽  
Chronic Obstructive ◽  
Obstructive Pulmonary Disease ◽  
And Control ◽  
The Impact

This chapter describes the hazards for construction workers, with a particular focus on injuries as well as exposures to hazardous chemicals and dusts. A section describes hazardous exposures to lead and other heavy metals. Another section describes noise exposure. The impact of musculoskeletal disorders among construction workers is then discussed. A section on respiratory diseases focuses on asbestosis, silicosis, chronic obstructive pulmonary disease, and asthma. Exposures known to cause dermatitis and cancer are reviewed. There is a discussion of engineered nanomaterials as a potential emerging hazard. Various approaches to prevention and control, including regulations and health services, are described.

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